BT line AC Balance?

[rbel]

The saga of my FTTC connection speed is still dragging on (see FTTC
speeds 18/08).

The latest BTOR engineer spent a couple of hours here today and
carried out similar tests to those performed during previous visits.

Whilst he confirmed that virtually all of the tests gave a good
'green' result he was concerned that the 'AC balance' produced an
'amber' reading of 51 whereas it should be >60. This is apparently
something to do with 'line balance'. Does anyone know any more about
this and its implications?
--
rbel

[The Natural Philosopher]

sunds like common mode rejection ratio, probably in dB, which is how
good the line is at rejecting interference from 'far field'

I'd expect a poor line to end up with poor night time performance
(MW/LW) and a high SNR ratio/low speed.


--
Ineptocracy

(in-ep-toc’-ra-cy) – a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

[kraftéé]

"rbel" wrote in message news:njr559tv061g4oo4f...@4ax.com...

You've probably got a iffy connector somewhere in the link between your FTTC
cab and yourself.

A bugger to find if everything else is green

[rbel]

On Mon, 7 Oct 2013 19:45:23 +0100, kraftיי <kraftיי@b&e-cottee.me.uk>
wrote:

The BTOR engineer thought that it could be between the NTE5 in my
property and the first junction box in the road but for some reason he
wanted someone else to look at it. If the problem is in this run of
wiring I imagine that it can be repaired/replaced.

Is this type of fault and indicated extent of an actual 51 compared to
the required 60+ likely to have a significant impact on the speed?
--
rbel

[kraftéé]

"David Hough" <noone$$@llondel.org> wrote in message
news:pklcia-...@llondel.org...

> wrote:
>>
>> The BTOR engineer thought that it could be between the NTE5 in my
>> property and the first junction box in the road but for some reason he
>> wanted someone else to look at it. If the problem is in this run of
>> wiring I imagine that it can be repaired/replaced.
>>

> They have different people responsible for different bits of the kit. He's
> probably not qualified to climb poles or dig holes, either of which might
> be
> needed for fixing external plant.

None of the field crew are allowed to dig holes any more, all goes out to
contract as for climbing poles...with the pole test schedule so far behind
it's getting to be a hoist permanently required, but that's only if the
field person has been trained to operate it as well. But seriously I think
you may be correct, the OR person most probably hasn't had any basic
training in going into UG structures so would be unable to do so, but he
should have called for a UG trained assist so that they could work together
to fix the problem.

[kraftéé]

"kraft��" <kraft��@b&e-cottee.me.uk> wrote in message
news:rqWdnWZgN7yby8nP...@bt.com...

In an ideal world of course.

[Mark Carver]

kraftיי wrote:

> None of the field crew are allowed to dig holes any more, all goes out
> to contract as for climbing poles...with the pole test schedule so far
> behind it's getting to be a hoist permanently required, but that's only
> if the field person has been trained to operate it as well.

Yes, tell me about it !! My folks had a noisy line recently, the first BT-OR
guy came, and with his test kit indentified there was an HR fault on the line.
Their line comes in overhead. However the chap didn't check either
the junction box on their eaves, nor climbed any of the poles along the road.
All he did was visit the cabinet about 400 yds away, and remake a connection
there. He proclaimed that was where the problem was. That night the noise
returned, my folks (well me actually) reopened the fault, and a week later
another chap came. He ran some tests, and said the problem was most probably
on the pole outside their property. He made a phone call, and 20 mins later a
cherry picker arrived ! Up he went, and quelle surprise, the joint on top
of the pole had almost totally corroded away. Problem fixed. Only took another
three weeks for BT's crappy DLM system to increase their ADSL sync speed from
a meg, back to their usual 15 Mb/s


--
Mark
Please replace invalid and invalid with gmx and net to reply.

[kraftéé]

"Mark Carver" <mark....@invalid.invalid> wrote in message
news:bbla91...@mid.individual.net...

3 Weeks......

You should have raised another fault (honest).

[The Natural Philosopher]

On 09/10/13 19:40, kraftéé wrote:
>
> "Mark Carver" <mark....@invalid.invalid> wrote in message
> news:bbla91...@mid.individual.net...

THis is odd, because every time an engineer 'fixed' my lines, they
reset the noise margin explicily and my ISP will also do this (request
that BT do it) any time I ask, usaully within 2 hours.

[Jim]

On Mon, 07 Oct 2013 21:12:56 +0100, rbel wrote:

>The BTOR engineer thought that it could be between the NTE5 in my
>property and the first junction box in the road but for some reason he
>wanted someone else to look at it. If the problem is in this run of
>wiring I imagine that it can be repaired/replaced.
>
>Is this type of fault and indicated extent of an actual 51 compared to
>the required 60+ likely to have a significant impact on the speed?

If there's an imbalance in the twisted pair, the line will be
more susceptible to external noise from MF/HF radio, particularly
when MW propagation peaks in the evening and early morning.

--

:: Jim ::

UKIP-BNP Migration Policy:
'Go back to where you came from!'
Tory Migration Policy:
'Contact the Home Office for help
to go back to where you came from'.

[Peter Crosland]

On 09/10/2013 16:15, Mark Carver wrote:

Your ISP should be able to reset the speed so the sync will be
corrected. No say should it take three weeks!


--
Peter Crosland

[rbel]

On Wed, 09 Oct 2013 19:59:28 +0000, Jim <Che...@hotmail.com> wrote:

>On Mon, 07 Oct 2013 21:12:56 +0100, rbel wrote:
>
>>The BTOR engineer thought that it could be between the NTE5 in my
>>property and the first junction box in the road but for some reason he
>>wanted someone else to look at it. If the problem is in this run of
>>wiring I imagine that it can be repaired/replaced.
>>
>>Is this type of fault and indicated extent of an actual 51 compared to
>>the required 60+ likely to have a significant impact on the speed?
>
> If there's an imbalance in the twisted pair, the line will be
>more susceptible to external noise from MF/HF radio, particularly
>when MW propagation peaks in the evening and early morning.

Interesting - many thanks.

How would this make itself evident? I take it that it is different to
REIN? Stability is good with no dropped connections and speed, as
checked using the BTW site, is fairly constant throughout the day.
--
rbel

[Mark Carver]

On 09/10/2013 21:51, Peter Crosland wrote:> On 09/10/2013 16:15, Mark

Carver wrote:

>> three weeks for BT's crappy DLM system to increase their ADSL sync

>> from a meg, back to their usual 15 Mb/s
>
> Your ISP should be able to reset the speed so the sync will be
> corrected. No say should it take three weeks!

I dare say they (Plusnet) could have done. However, my folks weren't
troubled by the low speed, in fact they were unaware, their internet use
and activity is very low. I was intrigued to see how quickly the speed
would restore with everything left to its own devices. You certainly
can't accuse BT of having any hysteresis in their DLM system, that's for
sure !

[Peter Able]

<rbel> wrote in message news:3kib59hjqj3afqepj...@4ax.com...

> On Wed, 09 Oct 2013 19:59:28 +0000, Jim <Che...@hotmail.com> wrote:
>
>> If there's an imbalance in the twisted pair, the line will be
>>more susceptible to external noise from MF/HF radio, particularly
>>when MW propagation peaks in the evening and early morning.
>
> Interesting - many thanks.
>
> How would this make itself evident? I take it that it is different to
> REIN?

Similar and different. It really depends on your distance from the source
of the interference. When the source is more than, say, 50 miles away you
tend to "receive" it via reflection/refraction off the ionosphere - and this
"skywave" propagation is much stronger during darkness hours. The
difference between REIN and radio is that the radio source is intentionally
connected to a aerial designed and intended to radiate, whereas REIN uses
the local wiring as a make-do aerial.

No adsl line is pefectly balanced so everyone will get a worse "noise
margin" - or whatever your modem documents call it - if they disconnect and
reconnect at midnight, compared to doing the same at midday. I think that
my system is quite well-balanced, and that difference in noise margins here
is about 3 to 4dB. As Jim said, it is all to do with being "more
susceptible". If you notice a difference of, say, more than 8dB - then MF
radio pick-up MAY be an issue.

PA

[Peter Able]

"Peter Able" <stuck@home> wrote in message
news:tZ-dncWCrYtJMsvP...@brightview.co.uk...

Incidentally, most competent ADSL faceplates include a component which
should re-balance your ADSL reception with respect to MF radio signal
pick-up. For older faceplates items such as the iPlate AKA "BT Broadband
Accelerator" bring them up to the same standard. It is having one of
these - and finding that it didn't really improve things here that justifies
my previous "I think that my system is quite well-balanced" statement. ;-}}

PA

[rbel]

>Incidentally, most competent ADSL faceplates include a component which
>should re-balance your ADSL reception with respect to MF radio signal
>pick-up. For older faceplates items such as the iPlate AKA "BT Broadband
>Accelerator" bring them up to the same standard. It is having one of
>these - and finding that it didn't really improve things here that justifies
>my previous "I think that my system is quite well-balanced" statement. ;-}}
>

Many thanks for the explanation.
I imagine that it should manifest itself in fairly frequent dropped
connections?
The current FTTC connection is via the VDSL faceplate on the NTE5.
--
rbel

[Peter Able]

<rbel> wrote in message news:dbfd599e616r22t3u...@4ax.com...

Well, yes, but so many other things could cause this, too. I've no fibre
experience, but in ADSL, the requirement for a 6dB noise margin during a
reconnect should deal with a normal day/night variation due to radio
signals.

At least with your connection, it is only the line between the cabinet and
your location that is subject to this problem!

PA

[kraftéé]

"The Natural Philosopher" <t...@invalid.invalid> wrote in message
news:l348qu$qoe$1...@news.albasani.net...

If the job came out as a line fault it will be dealt as such. The Openreach
engineer is only empowered to do the job as it is stated on the job
description.

Now if they had a DSL fault they could go thru the hoops to get the profile
adjusted but on a line fault they wouldn't receive the data required to
access the system.

[Mark Carver]

On 20/10/2013 02:39, kraftéé wrote:

>>>> three weeks for BT's crappy DLM system to increase their ADSL sync
>>>> speed from a meg, back to their usual 15 Mb/s
>>>
>>> 3 Weeks......
>>>
>>> You should have raised another fault (honest).

>> THis is odd, because every time an engineer 'fixed' my lines, they
>> reset the noise margin explicily and my ISP will also do this (request
>> that BT do it) any time I ask, usaully within 2 hours.

> If the job came out as a line fault it will be dealt as such. The
> Openreach engineer is only empowered to do the job as it is stated on
> the job description.

> Now if they had a DSL fault they could go thru the hoops to get the
> profile adjusted but on a line fault they wouldn't receive the data
> required to access the system.

Yes, the fault was reported as an 'audio' only one, following general
advice I've often seen in here and in other places, *never* to mention
the ADSL service is also affected to BT's script monkies. That just
adds to the chaos AIUI ?